This invention relates to guns and in particular guns suitable for firing pellets using compressed gas.
A variety of air and compressed gas guns are known at this time and they are capable of firing a variety of projectiles including BB's, lead pellets and paint balls. One common type of gun uses small cylinders containing compressed CO.sub.2. These metal cylinders have an end that can be punctured in order to release the CO.sub.2 gas. Guns of this type have been used for quite some time to fire lead pellets for purposes of game shooting and target shooting and more recently they have been developed and adapted to fire paint pellets. These pellets are in the form of spherical gelatin capsules filled with a marking solution or paint. Guns that fire paint pellets are used in mock "war games" where the users of the guns attempt to hit other game participants with a paint pellet. Protective wear is worn to prevent injury during such games.
Recently issued Canadian patent No. 1,264,128 dated Jan. 2, 1990, and entitled "AIR GUN", describes a gun for firing paint pellets wherein a hammer mechanism is mounted in a rear end of the pellet-firing barrel. The gas cylinder for this gun is mounted in an upper barrel directly above and parallel to the pellet-firing barrel. This known gun has a gas valve system arranged in the lower barrel in front of the hammer. The gun is fired by a trigger mechanism that includes a trigger and a pivoting trigger operated lever, the rear end of which is lowered by pressing the trigger. The lever rear end is returned to its original position by a spring after release of the trigger. The lever has an upstanding projection on its rear end which engages in an annular groove that extends about the hammer.
Another paint ball firing gun that employs compressed gas is shown in applicant's U.S. Pat. No. 5,078,118 dated Jan. 7, 1992. In this air gun, there is a housing or "donkey" mounted at the rear end of the breech, which housing is used to attach the standard gas cylinder to the rear end of the breech. This housing includes a gas passageway for delivering compressed gas from the cylinder to a small passageway extending along the top of the breech. A barrel is attached to the front end of the breech by a standard thread connection.
One difficulty with many known guns is that they must be made from relatively expensive, metal parts in order that the gun will have the necessary strength to withstand the loads thereon, including shock loads. Also, some pares must be machined to fairly close tolerances in order to work properly and in a reliable fashion. It will be appreciated that machined metal parts can increase the cost of a gun substantially and it is therefore desirable to avoid the need for such parts where possible. It is also desirable to reduce the number of parts required for the operation of an air gun, again in order to reduce costs.
It is an object of the present invention to provide a gun which is self-cocking and which employs a relatively simple and reliable sear mechanism capable of releasing the hammer with each pull of the trigger.
It is a further object to provide a unique pin connection for mounting the valve mechanism of an air gun in its breech. The pin connection includes an elastomeric bumper which reduces shock loading on the frame of the gun, thus permitting the frame to be made from an inexpensive material such as plastics.
It is an additional object of the invention to provide a gun for firing pellets that has a unique housing or "donkey" for holding a source of compressed gas detachably connected to the rear portion of an exterior frame that forms the breech. This housing is connected by means of pins which enable the housing to be easily connected and disconnected from the rest of the gun.
There is disclosed herein an inexpensive gun wherein the breech is made from top and bottom frames which are detachably connected together by retaining pins. This frame construction can quickly and readily be disassembled.